Sardet C, Gillot I, Ruscher A, Payan P, Girard J-P, de Renzis G
Unité de Biologie Cellulaire Marine, URA 671 CNRS, Université de Paris VI, Station Zoologique, 06230 VILLEFRANCHE-SUR-MER, France, Phone 93 76 37 70, Fax no 93 76 38 93.
Department of Experimental Zoology, Utrecht, The Nederlands.
Dev Growth Differ. 1992 Feb;34(1):37-42. doi: 10.1111/j.1440-169X.1992.00037.x.
We have studied the effect on sea urchin eggs of ryanodine, a plant alkaloid that causes muscle contraction by opening calcium channels in the sarcoplasmic reticulum terminal cisternae. Ryanodine, although it is less effective that IP , produces full or partial activation in 62% of injected sea urchin eggs. In addition ryanodine inhibits in a dose dependant manner Ca pumping in the isolated egg cortex or in eggs permeabilized with digitonin. Efflux experiments show that in fact ryanodine as IP stimulates the release of calcium sequestered intracellularly. We further show that these effects of ryanodine are inhibited by Mg , ruthenium red and heparin. Our results suggest that ryanodine-sensitive intracellular calcium channels exist in the sea urchin egg.
我们研究了植物生物碱莱克多巴胺对海胆卵的影响，莱克多巴胺通过打开肌浆网终末池中的钙通道引起肌肉收缩。莱克多巴胺虽然比肌醇磷酸（IP）的效果差，但在62%的注射海胆卵中能产生完全或部分激活。此外，莱克多巴胺以剂量依赖的方式抑制分离的卵皮质或用洋地黄皂苷通透处理的卵中的钙泵。外流实验表明，实际上莱克多巴胺与肌醇磷酸一样能刺激细胞内储存钙的释放。我们进一步表明，莱克多巴胺的这些作用受到镁、钌红和肝素的抑制。我们的结果表明，海胆卵中存在对莱克多巴胺敏感的细胞内钙通道。
